diff --git a/csrc/u8g_com_atmega_hw_spi.c b/csrc/u8g_com_atmega_hw_spi.c
index 67dc0371..dfed4a4f 100644
--- a/csrc/u8g_com_atmega_hw_spi.c
+++ b/csrc/u8g_com_atmega_hw_spi.c
@@ -149,7 +149,7 @@ uint8_t u8g_com_atmega_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void
       else
       {
 #if defined (__AVR_ATmega128__)
-	PORTB &= ~_BV(1);
+        PORTB &= ~_BV(1);        /* SCK = 0 */
 #else
         PORTB &= ~_BV(5);        /* SCK = 0 */
 #endif